JP2919615B2 - INK, INK JET RECORDING METHOD USING THE SAME, AND APPARATUS USING THE INK - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink, an ink-jet recording method using the same, and an apparatus using the ink. More specifically, the present invention relates to non-coated paper such as fine paper, copy paper, bond paper, report paper, and the like. Ink discoloration of images recorded on so-called plain paper with high print density and improved water resistance, as well as on coated paper having a recording material on the surface of an ink receiving layer consisting of a binder and a pigment, so-called coated paper The present invention also relates to an improved ink, an ink jet recording method, a recording unit, an ink jet recording apparatus, and an ink cartridge.

[0002]

2. Description of the Related Art Conventionally, an aqueous ink obtained by dissolving a water-soluble dye in an aqueous medium has been used as an ink for ink jet recording. In these conventional inks, (1) an image having a sufficient density is provided, (2) good drying properties on a recording material, (3) little bleeding of a recorded image, and (4) water That the recorded image does not flow out even when it comes into contact with alcohol, etc., or that it is sufficiently legible even if it flows out (water resistance); (5) the light resistance of the recorded image is excellent; (6) the pen tip or nozzle tip (7) When recording continuously, when starting recording after leaving for a long period of time, there is no problem such as blurring of the recorded image (ejection stability), (8) When storing, ink Is stable, (9) When used, there is no problem even if it comes into contact with the members constituting the recording means, (10) There is no problem in the safety of the user, etc. In the inkjet recording system that uses energy, In addition to the serial request item (11) that does not adversely affect the excellent and thermal energy generating means in heat resistance, it is required.

Examples of specific dyes include, for example, C.I. in both the monocolor and full-color images in the field of ink jet recording. I. Food Black 2 has been mainly used (JP-A-59-93766 and JP-A-59-93766).
-93768). C. I. Food black 2
Is excellent in that an image having a sufficient density is obtained, but has a problem in light resistance and water resistance. That is, if the printed matter is exposed to light for a long time or is posted near a copying machine, the black color changes to brown,
The image quality changes significantly. In addition, there is a problem that it is difficult to read when a test is performed on the assumption that water has been spilled on an image.

JP-A-1-135880 discloses an ink in which discharge stability, water resistance of an image, and the like are improved by introducing at least one specific structural unit into a dyed structure. Furthermore, Japanese Patent Application Laid-Open No. 1-193375 discloses a black ink which has a high affinity for a recording material, has excellent fixability and water resistance, and gives good print quality to plain paper. Tokiko 62-102
No. 74 discloses an ink in consideration of ejection stability, light fastness of an image, and the like. First, the ink must have the performance adapted to the recording system, and after satisfying the performance, it must be capable of exhibiting the performance as a printed matter, that is, the quality, sufficient performance of the fastness. I have. However, satisfying all of the various required performances is considerably difficult as seen in the above-mentioned known examples.

Although the print quality depends on the performance of the dye itself, it largely depends on the liquid medium in the ink. It is the fastness of the printed matter that is directly controlled by the performance of the dye. Light fastness is an important problem among fastnesses, and the solution has been conventionally determined by selecting a dye having excellent light fastness as described above. In the past, this problem was not so much a problem, but as a result of many problems being solved by technological advances, the problem of discoloration has come to be noticed. In particular, the effect is significant for a large amount of black ink, and in the case of a full-color image, the discoloration causes a sharp decrease in image quality.

[0006] The problem of discoloration progresses even in a room where direct sunlight is not applied, and also depends on the type of recording material for forming an image, and is remarkable in paper containing a pigment such as silica. Conventionally used C.I. I. Food Black 2 did not solve this problem. By selecting a dye having good light fastness, C.I. I. Attempts have been made to solve the disadvantages of Food Black 2, and satisfactory results have been obtained with plain paper. However,
In the case of a so-called coated paper in which an ink receiving layer containing a pigment and a binder is formed on a base material such as paper, in order to enhance the image quality such as the coloring property of the dye, sharpness, and resolution, on plain paper, However, even if the ink has little problem, the discoloration is remarkable, and it cannot be solved simply by selecting a dye having good light resistance.

[0007]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an ink which satisfies the above-mentioned general requirements and which can provide an image which does not cause a discoloration problem even on coated paper. That is, the influence of the ink jet recording method and the device using such an ink.

[0008]

The above object is achieved by the present invention described below. That is, the present invention provides an ink containing a recording agent and a liquid medium in which the recording agent is dissolved or dispersed, wherein the recording agent contains a compound represented by the following general formula (A),

Embedded image (Where n represents 0 or 1, and R ₁ , R ₂ or R ₃ is each selected from the group consisting of a hydrogen atom, a methyl group, a methoxy group, a hydroxyl group, an amino group, an acetylamino group and a sulfonic acid group. And M represents an alkali metal, ammonium, or organic ammonium.) In an ink jet recording method for performing recording on a recording material using ink droplets, the ink is the above-described ink, In a recording unit including a stored ink storage unit and a head unit for discharging the ink as ink droplets, the recording unit includes the above-described ink, and includes an ink storage unit that stores the ink. In the ink cartridge, the ink is the above-mentioned ink, and the above-mentioned recording unit An ink jet recording apparatus provided with the above, wherein the ink is the above-mentioned ink.

[0009]

According to the present invention, an ink which gives an image with less discoloration in a room even on coated paper by using the above compound as a coloring material of the ink, an ink jet recording method using the same, and an ink The equipment used is provided.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the present invention will be described in more detail with reference to preferred embodiments. Preferred specific examples of the compound (dye) represented by the general formula (A), which mainly characterizes the present invention, include the following compounds (dyes).

Embedded image Specific Example No. 1

Embedded image Specific Example No. 2

Embedded image Specific Example No. 3

Embedded image Specific Example No. 4

Embedded image Specific Example No. 5

Embedded image Specific Example No. 6

Embedded image Specific Example No. 7

Embedded image Specific Example No. 8

Embedded image Specific Example No. 9

Embedded image Specific Example No. 10

Embedded image Specific Example No. 11

Embedded image Specific Example No. 12

Among the above dyes, those in which the position of the azo group bonded to the naphthalene ring is 2,7-position are more preferred. The dye used in the present invention is generally a sodium salt of a water-soluble group such as a sulfonic acid group, but the present invention is not limited to these sodium salts, and their counter ions are potassium, lithium, and ammonia. , Organic amines and the like are also effective, and the present invention also includes dyes containing these other counter ions.

The production of the above dye is described in "Theoretical Production" by Yutaka Hosoda.
It is synthesized as follows according to the usual method described in "Dye Chemistry". Synthesis Example Specific Example No. The second dye is synthesized as follows. 3 '
-Amino-4'-methoxyacetanilide is diazotized in a conventional manner and coupled with 2,5-dimethoxyaniline. Furthermore, it is diazotized with sodium nitrite and this is 2R
Coupling with acid, then diazotization with sodium nitrite. This is added to a solution of m-phenylenediamine-4-sulfonic acid and coupled at pH 4-5.
The dye is salted out with sodium chloride and filtered off. The procedure of dissolving this in water and repeating salting-out filtration with sodium chloride was repeated to remove impurities, followed by desalting and purification using an ultrafiltration apparatus (manufactured by Sartorius). 2 was obtained.

The amount of the dye used in the ink of the present invention is not particularly limited, but is generally from 0.1 to 15% by weight, preferably from 0.5 to 15% by weight of the total weight of the ink.
An amount occupying 10% by weight, more preferably 0.5 to 6% by weight is suitable. A suitable medium for use in the ink of the present invention is water or a mixed solvent of water and a water-soluble organic solvent.
As the water, it is preferable to use deionized water instead of general water containing various ions.

The water-soluble organic solvent used by mixing with water includes, for example, methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol,
tert-butyl alcohol, isobutyl alcohol, n-
Alkyl alcohols having 1 to 5 carbon atoms such as pentanol; amides such as dimethylformamide and dimethylacetamide; ketones or keto alcohols such as acetone and diacetone alcohol; ethers such as dioxane; Polyalkylene glycols; alkylene groups such as ethylene glycol, propylene glycol, butylene glycol, triethylene glycol, 1,2,6-hexanetriol, thiodiglycol, hexylene glycol, and diethylene glycol containing 2 to 6 carbon atoms Alkylene glycols; glycerin; ethylene glycol monomethyl (or ethyl) ether, diethylene glycol monomethyl (or ethyl) ether, triethylene glycol monomer Lower alkyl ethers of polyhydric alcohols such as ethyl (or ethyl) ether; lower dialkyl ethers of polyhydric alcohols such as triethylene glycol dimethyl (or ethyl) ether and tetraethylene glycol dimethyl (or ethyl) ether; sulfolane, N -Methyl-2-pyrrolidone, 1,3-dimethyl-
2-imidazolidinone and the like.

An appropriate organic solvent is selected from the above-mentioned organic solvents, and glycerin or polyethylene oxide having a polymerization degree of 3 to 6 is particularly preferable for preventing clogging of the ink.
In view of image density and ejection stability, a nitrogen-containing cyclic compound or a polyalkylene oxide ether compound is preferable, and a lower alcohol or a surfactant is preferably used for frequency response. Therefore, a preferred solvent composition in the present invention is a composition containing the above-mentioned various components in addition to water. The content of the water-soluble organic solvent in the ink is generally in the range of 2 to 80% by weight, preferably 3 to 70% by weight, more preferably 4 to 60% by weight of the total weight of the ink.

The amount of water used generally accounts for 10 to 97.5% by weight, preferably 35% by weight or more, more preferably 45% by weight or more of the whole ink. A large amount of low-volatile organic solvent remains in the formed image, which causes problems such as dye migration and image bleeding.

The ink of the present invention may further contain, if necessary, a pH adjuster, a viscosity adjuster, a surface tension adjuster and the like in addition to the above-mentioned components. Examples of the pH adjuster include various organic amines such as diethanolamine and triethanolamine; inorganic alkali agents such as hydroxides of alkali metals such as sodium hydroxide, lithium hydroxide and potassium hydroxide; and organic acids such as lithium acetate. Salts, organic acids and mineral acids.

The ink of the present invention as described above has a viscosity at 25 ° C. of 1 to 20 cps, preferably 1 to 15 cps.
And the surface tension is 30 dyn / cm or more, preferably 40 dyn / cm or more.
It preferably has physical properties of dyn / cm or more and a pH of about 4 to 10. An ink jet method is effective as a recording method using the ink of the present invention, and it is effective to use a coated paper as a recording material when an image having excellent clarity and resolution is required. It is a target.

The recording material used in the present invention may be any recording material such as ordinary plain paper (for example, high quality paper, medium quality paper, bond paper), code paper, OHP plastic film, and the like. However, a remarkable effect is exhibited particularly when coated paper is used. Generally, coated paper is
A high quality paper is used as a base material, and an ink receiving layer composed of a pigment and a binder is provided on the surface of the base material. In this case, a paper in which fibers of the base paper are mixed in the ink receiving layer is also included.

The ink of the present invention is particularly suitable when applied to an ink jet recording method of a type in which the ink is ejected by a bubbling phenomenon of the ink due to thermal energy,
Discharge is extremely stable and satellite dots are not generated. However, in this case, the thermal properties (for example, specific gravity, thermal expansion coefficient, thermal conductivity, etc.) may be adjusted.

The ink of the present invention is particularly preferably used in an ink jet recording method in which recording is performed by discharging droplets by the action of thermal energy, but it goes without saying that it can also be used for general writing instruments. As a method and apparatus suitable for performing recording using the ink of the present invention, a method and apparatus for applying thermal energy corresponding to a recording signal to ink in a chamber of a recording head and generating droplets by the thermal energy are known. No.

FIGS. 1, 2 and 3 show examples of the structure of a head which is a main part of the apparatus. The head 13 adheres a glass, ceramic or plastic plate having a groove 14 through which ink passes, and a heating head 15 (a head is shown in the figure, but is not limited to this) used for thermal recording. Is obtained. The heating head 15 includes a protective film 16 made of silicon oxide or the like, and an aluminum electrode 17.
-1, 17-2, heat generating resistor layer 18 made of nichrome or the like, heat storage layer 19, substrate 20 having good heat dissipation such as alumina
Consists of

The ink 21 has a discharge orifice (fine hole) 2
2, and a meniscus 23 is formed by a pressure (not shown). Now, when an electric signal is applied to the electrodes 17-1 and 17-2, the area indicated by n of the heating head 15 generates heat rapidly, and bubbles are generated in the ink 21 in contact with the area. Protrudes, the ink 21 is ejected, becomes a recording droplet 24 from the orifice 22, and flies toward the recording material 25. FIG. 3 shows an external view of a multi-head in which many heads shown in FIG. 1 are arranged. The multi-head is manufactured by closely contacting a glass plate 27 having a multi-groove 26 and a heating head 28 similar to that described with reference to FIG. FIG. 1 shows the head 13 along the ink flow path.
2 is a cross-sectional view taken along line AB in FIG.

FIG. 4 shows an example of an ink jet recording apparatus incorporating such a head. In FIG. 4, reference numeral 61 denotes a blade as a wiping member, one end of which is held by a blade holding member to become a fixed end, and forms a cantilever. The blade 61 is arranged at a position adjacent to the recording area of the recording head, and in this example, is held in a form protruding into the movement path of the recording head. Reference numeral 62 denotes a cap, which is disposed at a home position adjacent to the blade 61, and has a configuration in which the cap moves in a direction perpendicular to the direction in which the print head moves and comes into contact with the ejection port surface to perform capping. Further, 63 is an ink absorber provided adjacent to the blade 61, similar to the blade 61.
It is held in a form protruding into the movement path of the recording head.
The blade 61, the cap 62, and the absorber 63 constitute an ejection recovery unit 64, and the blade 61 and the absorber 6
3 removes moisture, dust and the like from the ink ejection port surface.

Reference numeral 65 denotes a recording head which has discharge energy generating means and discharges ink on a recording material facing a discharge port surface provided with discharge ports to perform recording, and 66 denotes a recording head on which the recording head 65 is mounted. A carriage for performing the movement 65. The carriage 66 is slidably engaged with the guide shaft 67, and a part of the carriage 66 is connected to a belt 69 driven by a motor 68 (not shown). As a result, the carriage 66 can move along the guide shaft 67, and the recording head 65 can move the recording area and the adjacent area. Reference numeral 51 denotes a paper feed unit for inserting a recording material, and 52 denotes a paper feed roller driven by a motor (not shown). With such a configuration, the recording material is fed to a position facing the ejection port surface of the recording head, and is discharged to a discharge section provided with a discharge roller 53 as recording proceeds.

In the above configuration, when the recording head 65 returns to the home position at the end of recording, the cap 62 of the head recovery unit 64 is retracted from the moving path of the recording head 65, but the blade 61 protrudes into the moving path. I have. As a result, the ejection port surface of the recording head 65 is wiped. When capping is performed with the cap 62 in contact with the ejection surface of the recording head 65, the cap 62 moves so as to protrude into the movement path of the recording head. Recording head 6
When 5 moves from the home position to the recording start position, the cap 62 and the blade 61 are at the same position as the position at the time of wiping described above. As a result, the ejection port surface of the recording head 65 is also wiped during this movement.

The above-described movement of the print head to the home position is performed not only at the end of printing and at the time of ejection recovery, but also at a predetermined interval while the printing head moves through the printing area for printing. Position, and the wiping is performed along with the movement. FIG. 5 is a diagram illustrating an example of an ink cartridge in which ink is supplied to a head via an ink supply member, for example, a tube. Here, reference numeral 40 denotes an ink storage section storing the supply ink, for example, an ink bag, and a rubber stopper 42 is provided at the tip thereof. By inserting a needle (not shown) into the stopper 42, the ink in the ink bag 40 can be supplied to the head. An ink absorber 44 receives the waste ink. It is preferable for the present invention that the ink container has a liquid contact surface with the ink formed of polyolefin, particularly polyethylene.

The ink jet recording apparatus used in the present invention is not limited to the one in which the head and the ink cartridge are separated from each other as described above, but is also suitable for the one in which they are integrated as shown in FIG. Used. In FIG. 6, reference numeral 70 denotes a recording unit, in which an ink storage unit storing ink, for example, an ink absorber is stored, and a head unit having a plurality of orifices in which the ink in the ink absorber is stored. It is configured to be ejected from 71 as ink droplets. As a material for the ink absorber,
The use of polyurethane is preferred for the present invention.
Reference numeral 72 denotes an atmosphere communication port for communicating the inside of the cartridge with the atmosphere. This recording unit 70 is used in place of the recording head shown in FIG.
6 is detachable.

[0029]

Next, the present invention will be described in more detail with reference to Examples and Comparative Examples. In the following description, "parts" are based on weight unless otherwise specified.

Examples (1) Preparation of Ink The components shown in Table 1 below were mixed and dissolved, and filtered using a filter having a pore size of 0.45 μm to obtain an ink of the present invention shown in Table 1 below. Table 1 No. No. of ink component used 1: Specific example No. No. 1 dye 3 parts Diethylene glycol 25 parts Pure water 72 parts No. 2: Specific example No. No. 2 dye 3 parts Diethylene glycol 20 parts N-methyl-2-pyrrolidone 15 parts Pure water 62 parts 3: Specific Example No. No. 3 dye 3 parts Polyethylene glycol 300 20 parts Pure water 77 parts 4: Specific example No. No. 4 dye 3 parts Ethylene glycol 25 parts Pure water 72 parts No. 5: Specific example No. 5 No. 5 dye 3 parts Pure water 82 parts Glycerin 15 parts No. 5 6: Specific Example No. No. 6 dye 3 parts Diethylene glycol 15 parts Ethylene glycol monoethyl 10 parts Ether pure water 72 parts 7: Specific example No. 7 No. 7 dye 3 parts Ethylene glycol 20 parts Isopropyl alcohol 5 parts Pure water 72 parts No. 7 8: Specific Example No. No. 8 dye 3 parts Glycerin 15 parts N-methyl-2-pyrrolidone 10 parts Pure water 72 parts 9: Specific example No. 9 No. 9 dye 3 parts Ethylene glycol 20 parts Ethanol 5 parts Pure water 72 parts No. 9 10: Specific example No. No. 10 dye 3 parts Diethylene glycol 25 parts Pure water 72 parts 11: Specific Example No. No. 11 dye 3 parts Polyethylene glycol 20 parts Isopropyl alcohol 10 parts Pure water 67 parts 12: Specific Example No. 12 dyes 3 parts Diethylene glycol 20 parts n-propyl alcohol 5 parts Pure water 72 parts

(2) Usage example Table 1 above was applied to an ink jet printer BJ-80A (manufactured by Canon, nozzle size 50 × 40 μm, number of nozzles 24) using a heating element as an ink ejection energy source.
(A) clogging at the time of reprinting after a temporary stop of printing, (b) clogging recovery at the time of reprinting after a long term stoppage of printing, and (C) Discoloration resistance was evaluated. Recording material A: coated paper NM for inkjet (trade name,
Recording material B: inkjet-coated paper FC-3 (trade name, manufactured by Jujo Paper) Recording material C: inkjet-coated paper IJ matt coat M (trade name, manufactured by Mitsubishi Paper) Recording material D: Copy paper Canon Paper Dry (trade name, manufactured by Canon Sales)

(3) Evaluation method and evaluation results (a) Clogging at the time of reprinting after temporarily stopping printing The printer was filled with a predetermined ink and alphanumeric characters were printed on the recording material C continuously for 10 minutes. After that, stop printing and leave for 10 minutes without cap etc. (20 ℃ ± 5 ℃,
(50 ± 10% RH), alphanumeric characters were printed again, and the determination was made based on the presence or absence of defective portions such as blurred or missing characters, but no defective portions were recognized. (B) Recoverability of clogging at the time of reprinting after printing has been stopped for a long period of time. 7 days (60 ° C, 10 ± 5)
% RH), the nozzle clogging recovery operation was performed, and the number of recovery operations until normal printing without character blurring, chipping, etc. was possible was determined. Normal printing was possible by the recovery operation. (C) Discoloration Resistance After solid printing of 10 mm × 30 mm on the recording materials A, B, C and D, the ozone concentration is always set to 0.
The printed matter was left for 30 minutes in a light-shielded tank maintained in the range of 3 ± 0.05% by volume, and the color difference (Δ
E * _ab ) was measured (based on JIS 28730). The results are shown in Table 2 below.

Table 2 ΔE * _ab No. Recording material A Recording material B Recording material C Recording material D 1 4.2 3.6 5.1 2.7 2 5.5 4.8 5.2 3.0 3 4.9 4.2 4.5 2.9 4 4.8 5.0 4.1 3.1 5 5.1 4.9 4.2 3.3 6 6.0 5.9 4.6 4.0 7 5.2 5.0 4.7 4.1 8 5.4 4.0 3.9 3.7 9 6.1 5.5 5.6 4.2 10 5.6 5.6 4.8 3.0 11 5.1 4.5 4.2 3.4 12 6.1 5.9 5.2 3.9 The color difference after exposing the printed matter to room light for 3 months was 3 or less in all cases. .

(Comparative Example) The components shown in Table 3 below were mixed and the same as in the Examples.
Were prepared, and solid recording was performed on recording materials A, B, and C by using the same recording apparatus as in the above-mentioned use example using each ink. When a test was similarly performed using the printed matter as a test piece in the above-mentioned ozone test tank, ΔE * _ab was all 20 or more. The color differences after exposure to room light for three months were all 12 or more. Table 3 No. No. of ink component used No. 13 below No. 13 dye 3 parts Diethylene glycol 25 parts Pure water 72 parts 14 No. below No. 14 dye 3 parts Ethylene glycol 20 parts Polyethylene glycol 300 10 parts Pure water 67 parts No. 15 No. No. 15 dye 3 parts Glycerin 15 parts Diethylene glycol monoethyl ether 10 parts Pure water 72 parts No. No. 16 below No. No. 16 dye 3 parts Diethylene glycol 20 parts Isopropyl alcohol 5 parts Pure water 72 parts No. No. 17 below. 17 dyes 3 parts Ethylene glycol 20 parts N-methyl-2-pyrrolidone 10 parts Pure water 67 parts

[0035]

Embedded image 13

Embedded image 14

Embedded image Fifteen

[Chemical Formula 30] 16

[Image Omitted] No. 31 17

[0036]

As described above, in the present invention, by using the compound (dye) represented by the general formula (A) as the dye in the ink, the performance required for printed matter on plain paper can be satisfied, and on the coated paper. Can provide an ink that gives an image with little discoloration. Further, it is possible to provide an image having high image quality, excellent resolution, little discoloration, and excellent fastness. In addition, the ink of the present invention sufficiently exhibits the above properties even when the pH of the ink is around neutral as 4 to 10,
It does not require the addition of a strong alkaline substance as described in JP-A-56-57862, and is preferable in terms of safety. Further, even when the ink of the present invention is applied to an ink jet recording method in which the ink is ejected by the action of thermal energy, no deposit is generated on the heater and the ink can be stably used for a long time. Also, there is no change in physical property values or precipitation of solid content during storage.

[0037]

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a head section of an ink jet recording apparatus.

FIG. 2 is a vertical sectional view of a head section of the ink jet recording apparatus.

FIG. 3 is an external perspective view of a head obtained by multiplying the head shown in FIGS. 1 and 2.

FIG. 4 is a perspective view illustrating an example of an inkjet recording apparatus.

FIG. 5 is a longitudinal sectional view of the ink cartridge.

FIG. 6 is a perspective view of an inkjet cartridge.

[Explanation of symbols]

 61: Wiping member 62: Cap 63: Ink absorber 64: Blow-out recovery unit 65: Recording head 66: Carriage

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) C09D 11/00-11/20 B41J 2/01

Claims (25)

(57) [Claims] 1. An ink containing a recording agent and a liquid medium in which the recording agent is dissolved or dispersed, wherein the recording agent contains a compound represented by the following general formula (A). Embedded image (Where n represents 0 or 1, and R ₁ , R ₂ or R ₃ is each selected from the group consisting of a hydrogen atom, a methyl group, a methoxy group, a hydroxyl group, an amino group, an acetylamino group and a sulfonic acid group. Represents a group, and M represents an alkali metal or ammonium or an organic ammonium.) 2. A compound represented by the general formula (A):
o. 1 to No. The ink according to claim 1, wherein the ink is at least one selected from 12. Embedded image Embedded image Embedded image Embedded image Embedded image Embedded image Embedded image Embedded image Embedded image 9 Embedded image 10 Embedded image 11 Embedded image 12 3. The ink according to claim 1, wherein the pH of the ink is in the range of 4 to 10. 4. The ink according to claim 1, wherein the recording agent accounts for 0.1 to 15% by weight of the total weight of the ink. 5. The ink according to claim 1, wherein the liquid medium contains a mixed solvent of water and a water-soluble organic solvent. 6. The ink according to claim 6, wherein the content of water is 10 to 97.
The ink according to claim 5, which accounts for 5% by weight. 7. The ink according to claim 5, wherein the content of the water-soluble organic solvent accounts for 2 to 80% by weight of the total weight of the ink. 8. The ink according to claim 1, which is used for ink jet. 9. An ink jet recording method for performing recording on a recording material using ink droplets, wherein the ink is used.
An ink jet recording method, characterized by being the ink described in (1). 10. The ink jet recording method according to claim 9, wherein the recording material is uncoated paper or coated paper. 11. The ink jet recording method according to claim 9, wherein the ink is ejected by applying thermal energy to the ink. 12. A recording unit, comprising: an ink storage section for storing ink; and a head section for discharging the ink as ink droplets, wherein the ink is the ink according to claim 1. unit. 13. The head according to claim 1, wherein the head is a head for ejecting ink droplets by applying thermal energy to the ink.
3. The recording unit according to 2. 14. The method according to claim 1, which is for inkjet recording.
3. The recording unit according to 2. 15. An ink jet recording method, wherein recording is performed by applying ink droplets to a recording material using the recording unit according to claim 12. 16. An ink cartridge having an ink storage portion for storing ink, wherein said ink is provided.
An ink cartridge characterized by being the ink described in (1). 17. The ink container according to claim 1, wherein the ink container has a bag structure.
7. The ink cartridge according to 6. 18. The ink cartridge according to claim 16, wherein the ink container has a liquid contact surface formed of polyolefin. 19. The ink cartridge according to claim 16, which is used for ink jet. 20. An ink jet recording method, wherein recording is performed by applying ink droplets to a recording material using the ink cartridge according to claim 16. 21. An ink jet recording apparatus comprising the recording unit according to claim 12, wherein the ink is the ink according to claim 1. Description: 22. The ink jet recording apparatus according to claim 21, further comprising a carriage of the recording unit. 23. An ink jet recording apparatus comprising the ink cartridge according to claim 16 and a recording head. 24. The ink jet recording apparatus according to claim 23, further comprising an ink supply system for supplying ink contained in the ink cartridge to a recording head. 25. The ink jet recording apparatus according to claim 23, wherein the recording head is a head that applies thermal energy to the ink to eject ink droplets.